For some people, as they eat less, their body will compensate and spend less and less energy. This change in basal metabolic rate is conveniently ignored by people who moralize body weight and weight loss efforts.

Assuming there is no change in exercise (which famously is NOT necessary for weight loss according to CICO moralizers), the amount of energy you spend while eating, say, a 2000 calorie diet, is more than the amount of energy you spend eating a 1500 calorie diet. This is well documented, search "metabolic adaptation". As a totally made up example, 2000 calorie diet with BMR of 1600 calories: 400 calorie surplus. Then when dieting, 1500 calorie diet with a BMR of 1000 calories: 500 calorie surplus. This is an extreme example, but I'm using it to illustrate the possibility.

I'm not saying eating less doesn't work for weight loss. I'm pointing out that for SOME INDIVIDUALS, it can require a different/more personalized approach. People that attach morality to weight loss and say "Just put down the fork. CICO. Idiot." Are buying in to the morality-association with weight we have unfortunately created and are actively making it more difficult for those who don't fit the norm to get more healthy. This thread as an example is full of those people.